<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>练习1-Dom</title>
</head>
<body>
    <form id="froms">
        <input type="checkbox" name="checkbox" value = "Java" >Java<br>
        <input type="checkbox" name="checkbox" value = "Python">Python<br>
        <input type="checkbox" name="checkbox" value = "C">C<br>
        <input type="checkbox" name="checkbox" value = "C++">C++<br>
        <input type="checkbox" name="checkbox" value = "C#">C#<br>
        <input type="checkbox" name="checkbox" value = "PHP">PHP<br>
        <input type="checkbox" name="checkbox" value = "Go">Go<br>
        <button type="button" id="tijiao">提交</button>
        <button type="button" id="quanxuan">全选</button>
        <button type="button" id="fanxuan">反选</button>
        <button type="button" id="quanbuxuan">全不选</button>
        <br>
        <input type="checkbox" name="checkbox2" value="is" id = "is">全选/不选<br>
    </form>
    <script src="01.js"></script>
</body>
</html>